U.S. patent application number 12/458711 was filed with the patent office on 2010-02-04 for electric rotary machine for vehicle.
This patent application is currently assigned to DENSO CORPORATION. Invention is credited to Koji Kondo.
Application Number | 20100026130 12/458711 |
Document ID | / |
Family ID | 41528355 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100026130 |
Kind Code |
A1 |
Kondo; Koji |
February 4, 2010 |
Electric rotary machine for vehicle
Abstract
An AC alternator for a vehicle has a rotor having a pair of pole
cores, and a stator. A plurality of claw magnetic pole parts are
formed in the pole cores. A permanent magnet is placed between a
pair of the claw magnetic pole parts so as to prevent leakage of
magnetic flux through the area between the adjacent claw magnetic
pole parts. The stator and the rotor are placed in the AC
alternator so that the stator faces the rotor at a spacing of
predetermined intervals. Flanges are formed at both sides of each
of the claw magnetic pole parts. The presence of the flanges fixes
the permanent magnets to the pole cores, and prevents them from
moving toward the outer radius direction measured from the rotary
shaft of the rotor. In particular, the thickness of each of the
flange parts is increased from the front end part to the bottom
part thereof.
Inventors: |
Kondo; Koji; (Kiyosu-shi,
JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Assignee: |
DENSO CORPORATION
Kariya-city
JP
|
Family ID: |
41528355 |
Appl. No.: |
12/458711 |
Filed: |
July 21, 2009 |
Current U.S.
Class: |
310/181 |
Current CPC
Class: |
H02K 21/044
20130101 |
Class at
Publication: |
310/181 |
International
Class: |
H02K 1/28 20060101
H02K001/28 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 29, 2008 |
JP |
2008-194252 |
Claims
1. An electric rotary machine for vehicles comprising: a rotor
comprising a pair of pole cores and a plurality of permanent
magnets, each of the pole cores having a plurality of claw magnetic
pole parts, and each of the permanent magnets being placed between
a pair of the claw magnetic pole parts adjacent to each other; and
a stator core placed in opposition to the rotor, wherein a flange
part is formed in a circumferential direction of the rotor on each
of the claw magnetic pole parts of the pair of the pole cores to
prevent the permanent magnets from moving toward an outer radius
direction of the rotor, and a thickness of the flange part is
increased from a front side to a bottom side of the flange
part.
2. The electric rotary machine according to claim 1, wherein an
outer surface of each of the permanent magnets has a shape to fit
the inner peripheral surface of the flange part of each of the claw
magnetic pole part.
3. The electric rotary machine according to claim 1, wherein an
outer peripheral surface of each of the flange parts has a constant
radius measured from a central axis of a rotary shaft of the
rotor.
4. The electric rotary machine according to claim 1, wherein a
spacing of a predetermined interval is formed between a stator core
of the stator and the flange parts of the claw magnetic pole parts
of the rotor cores.
5. The electric rotary machine according to claim 3, wherein a
radius measured from the rotary shaft is gradually decreased from a
front end part to a bottom part of the inner peripheral surface of
each of the flange parts.
6. The electric rotary machine according to claim 1, wherein each
of the flange parts is smoothly connected at the bottom part
thereof to the corresponding claw magnetic pole part.
7. The electric rotary machine according to claim 1, wherein each
of the claw magnetic pole parts has a concave part with which the
corresponding permanent magnet is fitted, and each of the permanent
magnets is assembled to a pair of the adjacent pole cores through
the concave parts of the claw magnetic pole cores of the adjacent
pole cores.
8. The electric rotary machine according to claim 1, wherein at
least a surface other than a bottom side surface in an outer
surface of each of the permanent magnets is covered with a covering
member made of non-magnetic material, where the bottom side surface
faces toward a rotary shaft side.
9. The electric rotary machine according to claim 1, wherein each
of the permanent magnets and the claw magnetic pole parts are
bonded by an adhesion member.
10. The electric rotary machine according to claim 8, wherein at
least two in the permanent magnet, the covering member, and the
claw magnetic pole part are bonded by an adhesion member.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is related to and claims priority from
Japanese Patent Application No. 2008-194252 filed on Jul. 29, 2008,
the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electric rotary machine
for vehicles such as passenger cars and trucks, in particular to an
electric rotary machine having an improved rotor structure
comprised of permanent magnets and pole cores with claw magnetic
pole parts.
[0004] 2. Description of the Related Art
[0005] Various types of electric rotary machines are mounted to
vehicles. For example, Japanese patent laid open publication NO. JP
H09-131030 has disclosed an alternate current (AC) generator or a
vehicular alternator for a vehicle. The conventional AC generator
has permanent magnets placed between adjacent claw magnetic pole
parts. The claw magnetic pole parts are annularity arranged on the
outer peripheral surface of a Lundell type rotor. The claw magnetic
pole parts are alternately faced to each other. The structural
combination of the claw magnetic pole parts and the permanent
magnets prevents leakage of magnet flux from the area between the
adjacent claw magnetic pole parts, and thereby increases the amount
of effective magnet flux.
[0006] In addition, a flange part is formed at the outer periphery
of each of the claw magnetic pole parts in the Lundell type rotor
in the AC generator having the above structure in order to fix the
permanent magnets in the diameter direction of the rotor against
the centrifugal force generated when the Lundell type rotor
rotates. Therefore the presence of the flange parts prevents the
permanent magnets from being moved toward the outer diameter
direction by the centrifugal force generated when the rotor
rotates.
[0007] However, the conventional AC generator of the above
structure has a drawback because no permanent magnet is placed
between the flanges of the adjacent claw magnetic pole parts which
are annularity arranged on the Lundell type rotor. Therefore the
above structure of the conventional AC generator allows the leakage
of magnet flux through the area between the adjacent flanges of the
adjacent magnetic claw pole parts, and thereby decreases the amount
of electric power of the AC generator. That is, the more the
thickness of each of the flanges formed on the claw magnetic pole
parts is decreased in the diameter direction (or radius direction)
of the rotor, the more the anti-centrifugal strength of the flanges
is decreased. In other words, a thin flange of the claw magnetic
pole part has a weak anti-centrifugal strength.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an
electric rotary machine for vehicles having flanges with improved
anti-centrifugal strength placed between adjacent claw magnetic
pole parts of pore cores in a Lundell type rotor. The electric
rotary machine according to the present invention increases the
output thereof such as the amount of electric power when the
electric rotary machine is an AC generator for vehicles, and the
output torque thereof when the electric rotary machine is an AC
motor.
[0009] To achieve the above purposes, the present invention
provides an electric rotary machine for vehicles. The electric
rotary machine has a rotor and a stator. The rotor is composed
mainly of a pair of pole cores and a plurality of permanent
magnets. Each of the pole cores has a plurality of claw magnetic
pole parts. Each of the permanent magnets is placed between a pair
of the claw magnetic pole parts adjacent to each other. The stator
core is placed in opposition to the rotor. In the electric rotary
machine, a flange part is formed in a circumferential direction of
the rotor to each of the claw magnetic pole parts of the pair of
the pole cores to prevent the permanent magnets from moving toward
an outer radius direction of the rotor. A thickness of the flange
part decreases toward the outside from the bottom side of the
flange.
[0010] This structure of the rotor allows the facing area of the
flange parts between the adjacent claw magnetic pole parts to be
decreased, and thereby decreases the leakage amount of magnetic
flux between the adjacent flanges, and increases the output (such
as the amount of electric power, and the output torque) of the
electric rotary machine according to the present invention. Still
further, because the thickness of each of the flange parts in the
radius direction of the rotor is gradually increased from the front
end part to the bottom part thereof, it is possible for the flange
parts of the claw magnetic pole parts of the pole cores in the
rotor to have an adequate strength (or an adequate anti-centrifugal
strength) against centrifugal force generated in the permanent
magnets towards the radius direction when the rotor rotates.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A preferred, non-limiting embodiment of the present
invention will be described by way of example with reference to the
accompanying drawings, in which:
[0012] FIG. 1 is a diagram showing an entire structure of an
alternate current (AC) generator as an electric rotary machine for
a vehicle according to the embodiment of the present invention;
[0013] FIG. 2 is a diagram showing a cross section of a part of a
Lundell type rotor in the AC generator shown in FIG. 1;
[0014] FIG. 3 is an enlarged diagram showing a flange part placed
on a claw magnetic pole part in a pole core of the Lundell type
rotor in the AC generator shown in FIG. 1;
[0015] FIG. 4 is a diagram showing a modification of the flange
parts formed on the claw magnetic pole parts in the pole cores of
the Lundell type rotor in the AC generator shown in FIG. 1;
[0016] FIG. 5 is a diagram showing another modification of the claw
magnetic pole parts in the pole cores of the Lundell type rotor in
the AC generator shown in FIG. 1;
[0017] FIG. 6 is a diagram showing another modification of the
permanent magnet placed between the adjacent claw magnetic pole
parts in the pole cores of the Lundell type rotor in the AC
generator shown in FIG. 1; and
[0018] FIG. 7 is a diagram showing another modification of the
flanges and the claw magnetic pole parts in the pole cores of the
Lundell type rotor of the AC generator shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Hereinafter, various embodiments of the present invention
will be described with reference to the accompanying drawings. In
the following description of the various embodiments, like
reference characters or numerals designate like or equivalent
component parts throughout the several diagrams.
Embodiment
[0020] A description will be given of an electric rotary machine
for a vehicle according to an embodiment of the present invention
with reference to FIG. 1 to FIG. 7.
[0021] FIG. 1 is a diagram showing an entire structure of an AC
generator as the electric rotary machine for a vehicle according to
the embodiment of the present invention. As shown in FIG. 1, the AC
generator 1 according to the embodiment is comprised of a Lundell
type rotor 2 (or the "rotor 2" for short), a stator 3, a front side
housing 4, a rear side housing 5, a brush assembly 6, a rectifier
device 7, a voltage regulator unit 8, and a pulley 9.
[0022] The rotor 2 has a plurality of pole cores 22, 23, permanent
magnets 29, exciting coils 21, and a rotary shaft 24. Each of the
pole cores 22 and 23 has a claw magnetic pole which is bent toward
the axial direction of the rotor 2. The claw magnetic pole parts of
the pole cores 22 and 23 are alternately arranged along the
rotational direction of the rotor 2 to form a north magnetic pole
(N pole) and a south magnetic pole (S pole). Each of the permanent
magnets 29 is placed between the adjacent claw magnetic pole parts
of the pole cores 22 and 23 which face each other in the axial
direction of the rotor 2. The exciting coil 21 is made of an
insulated copper wire. The exciting coil 21 is wound in a
concentric configuration to form a cylindrical shape in the rotor
2. Cooling fins 25 are fixed to the end surface in the axial
direction of the pole core 22 in the front side (or the pulley 9
side) of the AC generator 1 by welding (for example, by a
resistance projection welding). The cooling fins 25 have slant
blades to introduce cooling air from the front side, and then to
exhaust the cooling air toward the axial direction and the radial
direction of the rotor 2. Thus, the cooling fins 25 are an axial
type fan or a mixture of an axial and cyclone type fan.
[0023] Similarly, cooling fins 26 are fixed to the end surface in
the axial direction of the pole core 23 in the rear side of the AC
generator 1 by welding (for example, by a resistance projection
welding). The cooling fins 26 introduces cooling air from the rear
side and then exhaust the cooling air toward the axial direction of
the rotor 2. The above cooling fin assembly supplies the cooling
air to the permanent magnets 29 side of the rotor 2 in order to
prevent the temperature increase of the permanent magnets 29. This
can suppress deterioration of the magnetic characteristics and
enhance the reliability of the permanent magnets 29 fixed to the
rotor 2 by bonded member.
[0024] Slip rings 27 and 28 are fixed to the rear side of the
rotary shaft 24. The slip rings 27 and 28 are electrically
connected to both the ends of the exciting coil 21. The brush
assembly 6 has brushes 61 and 62 which are forcedly contacted onto
the slip rings 27 and 28. An exciting current flows from the
rectifier device 7 to the exciting coils 21.
[0025] The stator 3 has a plurality of slots formed in a stator
core 31. The stator core 31 faces the outer peripheral surface of
the rotor 2. A three phase stator winding 32 is wound at
predetermined intervals in the plurality of the slots. The
rectifier device 7 rectifies an alternate current (AC) voltage
induced in the three phase stator winding 32 and outputs a direct
current (DC) voltage. The rectifier device 7 is placed at the
opposed position to the pulley 9 through the rotor 2. The rectifier
device 7 is comprised of a positive electrode side discharging
plate and a negative electrode side discharging plate, and a
plurality of rectifier elements. The positive electrode side
discharging plate and the negative electrode side discharging plate
are fixed at predetermined intervals. The rectifier elements are
fixed with solder.
[0026] The front side housing 4 and the rear side housing 5
accommodate the rotor 2 and the stator 3. The rotor 2 is rotatably
supported around the rotary shaft 24 in the front side housing 4
and the rear side housing 5. The stator 3 is placed on the outer
surfaces of the pole cores 22 and 23 of the rotor 2 at a spacing of
predetermined intervals. The stator 3 is fixed to four supporting
parts 420 by bolts 34. The four supporting parts ate formed at
predetermined regular intervals along the rotational direction of
the rotor 2.
[0027] The voltage regulator unit 8 regulates the output voltage of
the AC generator 1 by adjusting the exciting current flowing in the
exciting coil 21. The voltage regulator unit 8 approximately
maintains constant the output voltage of the AC generator 1 which
is fluctuated by electric load and electric power generation
amount.
[0028] The pulley 9 transmits the rotational power of the internal
combustion engine (not shown) to the rotor 2 in the AC generator 1.
The pulley 9 is fastened to one end (in the opposite side to the
slip rings 27, 28) of the rotary shaft 24 by a nut 91. The rear
cover 92 accommodates the brush assembly 6, the rectifier device 7,
and the voltage regulator unit 8.
[0029] In the AC generator 1 having the above structure, the rotor
2 receives the rotational power transmitted from the internal
combustion engine (not shown) through a belt (not shown) and the
pulley 9, and thereby rotates. At this time, when an exciting
voltage is applied into the exciting coil 21 in order to excite the
claw magnetic pole parts of the pole cores 22 and 23, a three phase
AC voltage is generated in the AC generator 1. The rectifier device
7 outputs a predetermined DC current.
[0030] Next, a description will now be given of a peripheral
structure of the permanent magnets 29 placed in the claw magnet
pole parts in the rotor 2 of the AC generator 1.
[0031] FIG. 2 is a diagram showing a cross section of a part of the
Lundell type rotor 2 in the AC generator 1 shown in FIG. 1. I other
words, FIG. 2 shows a partial cross section of the rotor 2 in a
vertical direction of the rotary shaft 24 at a facing surface of
the pole cores 22 and 23. FIG. 3 is a diagram showing an enlarged
flange part placed on the claw magnetic pole parts in the pole
cores 22 and 23 shown in FIG. 2. Each of the permanent magnets 29
is placed between the claw magnet pole parts 22A and the 23A in a
pair of the pole cores 22 and 23 in the direction to prevent
leakage of magnetic flux. For example, when the exciting current
flows in the exciting coil 21, and the claw magnetic pole part 22A
of the pole core 22 becomes a north pole, and the other claw
magnetic pole part 23A of the pole core 23 becomes a south pole,
the side of the permanent magnet 29, which faces the claw magnetic
pole 22A becomes a north pole and the other side thereof, which
faces the claw magnetic pole part 23A becomes a south pole.
[0032] A flange part 22B is formed in the claw magnetic pole part
22A of the pole core 22, which projects from the outer peripheral
edge of the claw magnetic pole part 22A toward the radius direction
of the rotor 2 (toward the outer diameter side of the rotary shaft
24). The flange part 22B prevents the permanent magnet 29 from
moving toward the outer diameter side of the rotor 2. Similarly, a
flange part 23B is formed in the claw magnetic pole part 23B of the
pole core 23, which projects from the outer peripheral edge of the
claw magnetic pole part 23A toward the radius direction of the
rotor 2. The flange part 23B prevents the permanent magnet 29 from
moving toward the outer diameter side of the rotor 2.
[0033] The thickness of the flange part 22B in the diameter
direction is gradually increased from the thickness A of the front
side toward the thickness B of bottom side thereof, as shown in
FIG. 3.
[0034] The outer peripheral surface (which faces the stator core
31) of the flange part 22B has a constant radius round the rotary
shaft 24. This can keep a spacing of predetermined intervals
between the stator core 31 and the flange part 22B. In the inner
peripheral surface of the flange part 22B, the radius measured from
the rotary shaft 24 at the flange part 22B is gradually decreased
from the front end part to the bottom part of the of the flange
part 22B. Each of the permanent magnets 29 has a shape to fit the
inner peripheral surface of the flange parts 22B and 23B.
[0035] In structure of the AC generator 1 according to the
embodiment, the radius thickness of the front end part is thinner
than that of the bottom part of each of the flange parts 22B, 23B.
That is, it is possible to decrease the area in which the flange
parts 22B and 23B formed on a pair of the adjacent claw magnetic
pole parts 22A and 23A, face to each other. This structure of the
flange parts 22B, 23B prevents leakage of the magnetic flux between
the flange parts 22B, 23B, and allows the AC generator 1 to
increase the output amount of the electric power. Still further,
because the radius thickness of each of the flange parts 22B, 23B
is increased from the front end part to the bottom part thereof, it
is possible for the flange parts 22B, 23B to maintain the
anti-centrifugal strength against the centrifugal force of the
permanent magnets 29 when the rotor 2 rotates.
[0036] Because the permanent magnet 29 has a profile in which the
outer side in the radius direction of the permanent magnet 29 fits
into the inner peripheral surface of the corresponding flange parts
22B, 23B of the claw magnetic pole parts 22A, 23A, it is possible
for the entire inner surface of the flange parts 22B, 23B to
receive the centrifugal force from the permanent magnet 29. This
can prevent a part of the permanent magnet 29 from receiving an
excess stress, and from breaking.
[0037] Still further, according to the embodiment of the present
invention, the outer peripheral surface of each of the flange parts
22B, 23B has a same radius, and a spacing of predetermined
intervals is formed between the stator core 31 and the flange parts
22B, 23B. This structure allows the magnetic flux between the claw
magnetic pole parts 22A, 23A including the flange parts 22B, 23B
and the stator 3. This structure also increases the output amount
of electric power of the AC generator 1.
[0038] Still further, the radius measured to the inner peripheral
surface of each of the flange parts 22B, 23B from the rotary shaft
24 side of the rotor 2 is gradually decreased from its front end
part to its bottom part. This structure ensures the strength of
each of the flange parts 22B, 23B increasing.
(Modifications)
[0039] The concept of the present invention is not limited by the
above embodiment of the AC generator 1. It is possible to modify
the structure of the claw magnetic pole parts and the flange parts
in the rotor of the AC generator 1.
[0040] FIG. 4 is a diagram showing a modification of the flange
parts formed in the claw magnetic pole parts in the pole cores of
the Lundell type rotor in the AC generator 1 shown in FIG. 1. The
structure of the flange parts shown in FIG. 4 is a modification of
the structure of the flange part shown in FIG. 2.
[0041] As shown in FIG. 4, the bottom part of each of the flange
parts 22B, 23B has a round shape or a curved shape. This structure
allows that the inner peripheral surface of the flange parts 22B,
23N is smoothly fitted to the claw magnetic pole parts 22A,
23A.
[0042] FIG. 5 is a diagram showing another modification of the claw
magnetic pole parts in the pole cores of the Lundell type rotor in
the AC generator shown in FIG. 1. The structure of the claw
magnetic pole parts shown in FIG. 5 is a modification of the
structure of the claw magnetic pole parts shown in FIG. 2. As shown
in FIG. 5, each of the claw magnetic pole parts 22A, 23A has a
concave part that corresponds to the outer peripheral shape in the
circumferential direction of the permanent magnet 29. That is, a
part of the permanent magnet 29 is accommodated in or fitted to the
concave parts of the adjacent claw magnetic pole parts 22A and 23A
of the pair of the pole cores 22 and 23. The structure of the claw
magnetic pole parts shown in FIG. 5 allows the permanent magnets 29
to be fixed to the pole cores 22 and 23 regardless of the rotation
of the rotor 2. Further, this structure shown in FIG. 5 makes it
possible to easily assemble the permanent magnets 29 into the claw
magnetic pole parts of the pole cores of the rotor 2 in the AC
generator 1.
[0043] FIG. 6 is a diagram showing another modification of the
permanent magnet placed between the adjacent claw magnetic pole
parts in the pole cores of the Lundell type rotor in the AC
generator shown in FIG. 1. The structure of the permanent magnets
shown in FIG. 6 is a modification of the structure of the permanent
magnets shown in FIG. 2. As shown in FIG. 6, at least a surface
other than a bottom side surface in the outer surface of each of
the permanent magnets 29 is covered with a covering member 30. The
bottom side surface of the permanent magnet 29, which is not
covered with the covering member, is faced with the rotary shaft
side. The covering member 30 is made of non magnetic material. The
presence of the covering member 30 can decrease the stress applied
to the permanent magnets 29 during the rotation of the rotor 2.
Further, the presence of the covering member 29 prevents fragments
from being scattered when the permanent magnet 20 breaks. It is
preferable to completely cover the entire outer surface of the
permanent magnet 20 with the covering member 30. It is also
possible to apply the covering member 30 to each of the structure
of the rotor 2 shown in FIG. 2 and FIG. 4.
[0044] FIG. 7 is a diagram showing another modification of the
flanges and the claw magnetic pole parts in the pole cores of the
Lundell type rotor of the AC generator shown in FIG. 1. The
structure of the rotor shown in FIG. 7 is a modification of the
structure of the rotor shown in FIG. 2. As shown in FIG. 7, the
permanent magnet 29, the covering member 30, the claw magnetic pole
parts 22, 23 including the flange part 22B, the flange part 23B are
bonded by adhesive members 131, 132. The adhesive members 131, 132
are made of resin or rubber. It is also possible to bond a part of
the entire surface of the permanent magnet 29, the covering member
30, the claw magnetic pole parts 22, 23 including the flange part
22B by adhesive members. In the structure of the rotor shown in
FIG. 7, the adhesive members 131, 132 are added into the structure
of the rotor shown in FIG. 6. It is also possible to add the
adhesive members 131, 132 to the structure of each of the
structures of the rotor shown in FIG. 2, FIG. 4, and FIG. 5. In
those cases, the cooling fans 25, 26 provide cooling air to the
adhesive members 131, 132 to decrease the temperature of the
adhesive members 131, 132. This can increase the reliability of the
rotor in the AC generator 1 according to the present invention.
[0045] In the embodiment and the modifications previously
described, the concept of the present invention is applied to the
AC generator 1. The present invention is not limited by the
embodiment and the modifications previously described. For example,
it is possible to apply the concept of the present invention to
various types of electric rotary machines for vehicles, for
example, to an electric rotary machine having both functions of
generating electric power and providing output torque, or to an
electric rotary machine providing output torque without generating
electric power.
(Other features and effects of the present invention)
[0046] In the electric rotary machine as another aspect of the
present invention, it is preferable that an outer surface of each
of the permanent magnets has a shape to fit the inner peripheral
surface of the flange part of each of the claw magnetic pole part.
This structure allows that the entire surface of the permanent
magnet contacted to the corresponding flange parts can receive the
centrifugal force. That is, it is possible to avoid excess stress
being applied to a part of the permanent magnet. This prevents the
permanent magnets from being broken by such excess stress.
[0047] In the electric rotary machine as another aspect of the
present invention, it is preferable that an outer peripheral
surface of each of the flange parts has a constant radius measured
from a central axis of a rotary shaft of the rotor. It is also
preferable that a spacing of a predetermined interval is formed
between a stator core of the stator and the flange parts of the
claw magnetic pole parts of the rotor cores in the electric rotary
machine. This structure allows the amount of magnetic flux between
the stator and the claw magnetic pole parts including the flange
parts. As a result, it is possible to increase the output torque of
the electric rotary machine (when the electric rotary machine is an
AC motor), and to increase the amount of electric power generated
by the electric rotary machine (when the electric rotary machine is
an AC generator).
[0048] In the electric rotary machine as another aspect of the
present invention, it is preferable that a radius measured from the
rotary shaft is gradually decreased from a front end part to a
bottom part of the inner peripheral surface of each of the flange
parts. This structure can increase the strength of the flange parts
because of gradually increasing the thickness from the front end
part to the bottom part of each of the flange parts.
[0049] In the electric rotary machine as another aspect of the
present invention, it is preferable that each of the flange parts
is smoothly connected at the bottom part thereof to the
corresponding claw magnetic pole part. This structure decreases an
excess stress to be applied to the bottom part of each of the
flange parts. This structure can provide the flange parts formed in
the claw magnetic pole parts in the pole cores of the rotor with
the large anti-centrifugal strength against the centrifugal force
of the permanent magnets when the electric rotary machine
rotates.
[0050] In the electric rotary machine as another aspect of the
present invention, it is preferable that each of the claw magnetic
pole parts has a concave part with which the corresponding
permanent magnet is fitted, and each of the permanent magnets is
assembled to a pair of the adjacent pole cores through the concave
parts of the claw magnetic pole cores of the adjacent pore cores.
This structure provides improved and high reliability of supporting
the permanent magnets during both cases, the rotating state and
non-rotating state. This structure further provides easy assembling
of the permanent magnets to the pole cores of the rotor in the
electric rotary machine.
[0051] In the electric rotary machine as another aspect of the
present invention, it is preferable that at least a surface other
than a bottom side surface in an outer surface of each of the
permanent magnets is covered with a covering member made of
non-magnetic material, where the bottom side surface faces a rotary
shaft side. This structure decreases the amount of stress to the
permanent magnets by centrifugal force generated when the electric
rotary machine rotates. This structure further prevents fragments
of the permanent magnets from being scattered when the permanent
magnet is broken into the fragments.
[0052] In the electric rotary machine as another aspect of the
present invention, it is preferable that each of the permanent
magnets and the claw magnetic pole parts are bonded by an adhesion
member. It is also preferable that at least two of the permanent
magnet, the covering member, and the claw magnetic pole part are
bonded by an adhesion member. This structure further increases the
reliability of supporting the permanent magnets by the pole cores
of the rotor in the electric rotary machine.
[0053] While specific embodiments of the present invention have
been described in detail, it will be appreciated by those skilled
in the art that various modifications and alternatives to those
details could be developed in light of the overall teachings of the
disclosure. Accordingly, the particular arrangements disclosed are
meant to be illustrative only and not limited to the scope of the
present invention which is to be given the full breadth of the
following claims and all equivalents thereof.
* * * * *